[This story contains spoilers for “The Fleece Works Its Magic Too Well,” the season two finale of Percy Jackson and the Olympians.]

Percy Jackson and the Olympians has been a fairly faithful adaptation of author Rick Riordan’s beloved book series through its first two seasons — and Riordan, who is an executive producer of the Disney+ series and involved in its writing, has signed off on the changes that have been made.

The season two finale, released Wednesday, makes several changes from its source material, The Sea of Monsters: The climactic battle takes place at Camp Half-Blood rather than on Luke’s (Charlie Bushnell) ship the Princess Andromeda, and Percy (Walker Scobell) and Co. aren’t aided by Chiron (Glynn Turman) and his fellow centaurs, aka the Party Ponies. The episode also reveals that some demigods inside the camp have been secretly working with Luke to advance his war against the gods of Olympus.

No change is bigger — or promises to have more impact on the series going forward — than a flashback between Zeus (Courtney B. Vance), the king of Olympus, and his demigod daughter Thalia (Tamara Smart). After beating back Luke and his forces and using the Golden Fleece to restore Thalia’s tree, and therefore the barrier surrounding camp, Thalia herself is freed from the tree. That’s essentially where the book ends.

The show, however, takes things several steps further when Chiron reveals to Percy, Annabeth (Leah Sava Jeffries) and Grover (Aryan Simhadri) that he regrets “many things” — including that the story he told of Zeus turning Thalia into a tree after she sacrificed herself to save Luke and Annabeth is a lie.

“I think it’s a really interesting change,” Smart told The Hollywood Reporter. “To me, it’s extremely engaging with her personality, because it creates this spin on the narrative of the show. Book fans will know everything that happens in the book, and most of it, they’re going to want to see in the show. But some of it, I think, should be a surprise.”

This definitely counts as one. As Chiron relates, it’s not Thalia who faces down the Furies as she escorts Luke and Annabeth to camp. “The Furies … did not attack,” Chiron says. “Instead, they spoke — until they said too much.”

Zeus strikes down the Furies with a lightning bolt so that he can speak to his daughter about the Great Prophecy, which says that a child of one of the Big Three gods — Zeus, Poseidon and Hades — will either protect or destroy Olympus upon reaching the age of 16. Thalia, though, doesn’t care to listen and tells Zeus that she’s going to leave camp: “Hear my words — I don’t want to be your daughter,” she says. “And I will never be your weapon.”

Zeus, rather than continuing to try talking with Thalia, then turns her into the tree, ensuring that she can’t leave Camp Half-Blood. It’s a devastating revelation, particularly for Annabeth, who has carried guilt for years about what happened to Thalia. Chiron explains Zeus ordered him to lie about what happened, but the quest for the Golden Fleece made him realize that the Titan Kronos would use the fleece’s power “to raise his champion” — whom he suspects is Thalia.

Though the stakes are much, much higher than the average father-daughter argument, the scene between Zeus and Thalia also plays out like one that ends with a defiant teenager sent to their room.

Courtney B. Vance as Zeus in ‘Percy Jackson and the Olympians’ season two.

David Bukach/Disney

“He is Zeus, but you know, you don’t want to use your power on your daughter, right?” Vance told THR. “She’s your daughter, and she knows you. It’s very tricky. [Thalia’s attitude is] you can be Zeus with your friends, and your enemies, but you can’t be Zeus with me. I’m not having that, dad. Stop. And then he, instead of just taking a step back and saying ‘OK, honey, let’s talk about this later, because I really, I really need you to help me with this’ —to get her on [his] side, he just got Zeus-y, and that’s not good. So whatever the consequences are for that, I guess that’s what we’ll see coming up.”

Vance took over the role of Zeus after Lance Reddick, who played the god in season one, died in March 2023. Vance called Reddick “a dear friend” and said when he went to Vancouver to film, he asked to speak to the cast and crew and acknowledge why he was there.

“I just wanted to say that I’m just blessed to be here,” Vance recalled. “This is Lance’s role, and I hope you would allow me the opportunity to find my way. We had a moment of silence for people to honor him however they wanted to. He was Zeus. I didn’t want to take over without acknowledging him, and because I did that, they embraced me, which is all I wanted. It was a beautiful moment. It was a beautiful, cold day in Vancouver, and we began our process.”

Smart also has a connection to Reddick, having co-starred with him in Netflix’s Resident Evil series in 2022. She said that bond was part of why she wanted the role of Thalia, “although a lot of thought had to go behind it, especially the potential of me not booking it,” she said. “I didn’t want to feel that heartbreak, so I was definitely really thinking about it. But eventually I just realized, you know, you miss 100 percent of the shots you don’t take. So I had to go for it.”

Smart also appreciated the father-daughter dynamic at play in the scene. “We’ve all been angry at someone and had this kind of a conversation,” she said. “I think that the beautiful thing on that day was the support that we had for each other. We were good, and we weren’t actually fighting. We were checking in [on each other]. I think that as much as this show is fantasy, there are very real themes that are explored, an I think that it comforts people to know that these themes are universal for everyone. I wasn’t fully playing into my acting ability. I was pulling from real experience of being frustrated. I mean, when I was 16, I definitely had that kind of a conversation with my dad.”

Vance also noted that in playing Zeus, he tries to carry the mindset that as an all-powerful god, he doesn’t really have to consider the way his actions come across to others.

“When people feel that they’re better than [others], you see what that can negatively turn into, where people are things and objects for your pleasure, for you to get what you want. To work them until they die,” he said. “It’s very easy to use that model to play someone to whom people are expendable. They’re objects for you to be able to do whatever you want to do. That’s what I think happened with Zeus and his daughter — he forgot that she’s his daughter.”

Vance said he and the show’s producers are still discussing if he’ll appear in season three, which is based on The Titan’s Curse, the third book in Riordan’s original five-volume series. Smart, however, spoke to THR from the show’s set in Vancouver, where she’s currently filming.

“If you thought season two was amazing — to everyone who’s going to be reading this, I think that season three is just bigger and better in every way, shape and form,” she said. “There is so much action, there is so much storytelling, there is so much emotion, so much conviction. I was with most of the cast over the weekend, and we were just talking about the fact that we have given this our everything, and we will continue to give this our everything. Because from what we’ve seen and heard from season three so far, it’s going to be awesome.”

Smart said she couldn’t offer any more specifics on the coming season, but Disney+ stepped in to offer a brief peek at season three, which is set to premiere later this year. Watch it below.

The first two seasons of Percy Jackson and the Olympians stream on Disney+ and Hulu.